Paul: Thank you very much for the answer. Your answer is, however, actually why I would like the feature - to avoid Spotify to flow through the iOS (like Airplay does) But - I found a solution just today. I bought another ChromeCast Audio, plugged it into my Mac via Optical out on The ChromeCast and optical in on the Mac. I then use the fantastic (and free) LineIn software from you guys at RogueAmoeba to pass the digital signal from the ChromeCast to the System Audio. From here the Mac is connected to my DAC through USB and at the same time Airfoil cast the music to two other ChromeCast around the house. So - a hardware solution that solved my request! Thank you again for this fantastic update!